The invention relates to electrical power systems for aircraft. More specifically, the invention relates to an aircraft electrical power system including an air conditioning system generator.
In an electrical power system of an aircraft, electrical equipment onboard the aircraft is typically connected to one or more electrical buses, and electricity is supplied to the buses by electrical generators that are driven by the aircraft's main engines. When a piece of equipment such as a galley oven is turned on, it uses electrical power. As the generator delivers the power to the piece of equipment, it places a load on the main engine. Consequently, the main engine is forced to work harder and burn additional fuel. This increase in fuel consumption results in higher operating costs for the aircraft.
The electrical power system also includes power conditioning electronics, which adds weight to the aircraft. The main engine generators are operated at variable speeds (due to varying shaft speed of the main engine) and therefore supply ac power at variable or "wild" frequencies. However, the electrical equipment typically runs on dc power or ac power at a fixed frequency such as 115 vac at 400 Hz. Typically, a rectifier unit is used for converting the ac generator power to dc power, and an inverter is used for converting the dc power to ac power having a fixed frequency. An inverter might add ninety pounds of weight to the aircraft. The added weight also increases the fuel consumption.
Additionally, the inverter is expensive. An inverter might cost more than ten thousand dollars.
There is a need to reduce fuel consumption and costs associated with the electrical power system of an aircraft.